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The Brazilian Wandering
spider
(Phoneutria fera)
is regarded by
some as the most dangerous
spider in the world.
Aggressive and highly venomous,
it kills some 5 people across
the world annually.
It is named as such because it
was first discovered in
Brazil, though this genus is
known to exist elsewhere in
South and Central America. This
spider is a member of the
Ctenidae family of
wandering spiders.
The family of Ctenidae,
where both genera,
Cupiennius and Phoneutria,
belong to has to date more
than 500 valid, described
species. Most of them have
no common names. Phoneutria spp. is
actually a genus with five known
similar species whose members
are highly
venomous
and not reluctant to attack
people who appear threatening.
However, recent studies possibly
indicate (but not with any
irrefutable proof) that these
spiders only inject venom in
approximately one-third of their
bites and may only inject a
small amount in another third. Bites from these spiders may result in only a couple of painful pinpricks, or may involve full-blown envenomation; but in all cases, people bitten by a
Phoneutria, or any Ctenid, should seek immediate emergency treatment, as the venom can be life threatening.
P. fera and P. nigriventer are the two most commonly implicated as the most virulent of the
Phoneutria spiders.
P. nigriventer venom contains a potent neurotoxin, also known as PhTx3, which acts as a broad-spectrum calcium channel blocker that inhibits glutamate release, calcium uptake and also glutamate uptake in neural synapse. At deadly concentrations, this neurotoxin causes loss of muscle control, and breathing problems, resulting in paralysis and eventual asphyxiation. In addition, the venom causes intense pain and inflammation following an attack due to an excitatory effect the venom has on the serotonin 5-HT4 receptors of sensory nerves. This sensory nerve stimulation causes a release of neuropeptides
such as substance P which
triggers inflammation and pain.
Aside from causing intense pain, the venom of the spider can also cause priapism - uncomfortable erections that can last for many hours and lead to impotence. The venom may eventually be used in erectile dysfunction treatments. The Brazilian
Wandering
spider is reputed to
occasionally hide in clusters of
bananas. As a result, any
large spider appearing in a
bunch of bananas should be
treated with due care. This spider is called the
wandering spider because it
wanders the jungle floor, rather
than residing in a lair or
maintaining a web. This
attribute is another reason it
is considered so dangerous. In
densely populated areas,
Phoneutria species usually
search for cover and dark places
to hide during daytime, and this
may occur inside houses,
clothes, cars, boots, boxes and
log piles; thus generating
accidents when near people.
Information - Answers.com &
Wikipedia |
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9 March, 2008:
Unique wandering spider I know is phoneutria
nigriventer (mine) because phoneutria fera lives
at amazon jungle, too far from my state, and others species
lives in other countries such Bolivia and places at Central
America. This spider is not extremely rare, but it's not
easy to find. There are videos at youtube about this spider,
here one very interesting, this show the 'attack pose' (we
call this spider as 'armadeira') I don't do this on mine,
because I don't like to injury this animal.
http://www.youtube.com/watch?v=pfm9OFX_Q2M See ya. |
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